Persons of Hispanic origin constitute one of the largest and most rapidly growing populations in the United States today. This population has distinctive demographic characteristics, especially its low child mortality and relatively good child health. The historical background and experience of the Hispanic population is important for understanding conditions today. The starting point for that understanding is the early 20th century. In 1910, Hispanic people with origins in Mexico, Cuba, and Spain began to be numerous in the U.S. Despite their growing numbers and their importance for the United States in the later 20th century, we know very little about this earlier population. Limited research about Hispanic infant and child mortality, for example, has produced contradictory results. This project will produce a new source of data and analyze those data to develop a clear picture of child mortality in the Hispanic population in the early 20th century. In this research we wish to measure and understand levels of child mortality in several segments of the Hispanic population in the early 20th century. These results will serve as a baseline for future research. We also intend to evaluate hypotheses about differences among the Hispanics we study, and about differences between them and non-Hispanics living near them. In this analysis we will explore the role of contextual co-variates such as population density and crowding, group characteristics such as origin and generation, and individual characteristics such as occupation, employment, and literacy. We expect the answers to these questions to tell us more about the reasons for both historical and contemporary Hispanic demographic and health characteristics. The lack of adequate data for the study of the Hispanic population requires us to create our own data set. Local vital registration data did not exist in the early 20th century in many areas and where they did exist there were few separate tabulations by Hispanic origin or surname. The 1910 census, with its questions about children ever born, children surviving, age, and duration of marriage, constitutes an excellent alternative source with national coverage. The existing Public Use Micro Sample for 1910 is too small to include a useful number of Hispanics. We will therefore create a representative oversample of Mexican-, Cuban-, and Spanish-origin Hispanics in 1910. This sample will provide us with material for our research; it will later serve the research needs of other scholars.